package com.gao.test;

import java.sql.SQLOutput;

/**
 * @Author: ShanYuqing
 * @Version: v1.0
 */
public class regex {

    public static void main(String[] args) {
        String regex = "[a-zA-Z0-9]{2,4}";
        System.out.println("45455".matches(regex));
    }
}
